Carton stapling machine



May 30, 1950 o. E. LARSSON 2,509,870

CARTON STAPLING MACHINE Filed July 22, 1949 a? 3% ZM/M/n;

ATTOR N E Y I NVENTOR.

Patented May 30, 1950 UNITED STATES PATENT OFFICE Application July 22, 1949, Serial No. 106,175 In Sweden August 16, 1948 2 Claims.

This invention relates to carton stapling machines of the type comprising a frame, a stitching apparatus mounted thereon, and adjustable beams supporting two feed shafts having pulleys for conveyor belts for feeding carton blanks through the stitching apparatus.

The object of the invention is to provide a machine of the type indicated in which the operation of the stitching apparatus is started and stopped by the movement of the carton blanks and in which the positions of the first and the last staple in a series of staples and the spaces between consecutive staples can be conveniently adjusted.

I attain this object and other objects by mechanism illustrated in the annexed drawing, in which- Fig. 1 shows an elevation of a carton stapling machine viewed in the direction of movement of the carton blanks; Fig. 2 is a section taken along the line 2-2, Fig. 1; Fig. 3 is a circuit diagram of an electric initiating device; Fig. 4 illustrates a frictional clutch for the stitching apparatus; Fig. 5 shows diagrammatically displaceable contact members for the initiating device; and Fig. 6 is an end elevation of a carton blank in folded position, ready to receive staples.

Referring to the drawing, the stitching apparatus 22 is arranged at the central portion of the machine supported by a frame or support 28, the power input shaft M of the stitching apparatus extending laterally of the machine. The stitching apparatus is shown diagrammatically only and may be of any suitable construction. In parallel relation to shaft l4, two feed shafts and 2 are provided which are supported by beams 4 displaceably carried by stationary bars 29. The shafts l and 2 have mounted thereon pulleys 5 splined on the shafts so as to be displaceable thereon together with the beams but not rotatable relative to the shafts. Feed or conveyor belts 8 mounted on the pulleys 5 support the carton blank 9 which is kept in engagement with the conveyor belts 8 by means of pressure rollers I!) which are slightly conical having their smaller end faces directed toward the blank portions to be united by the staple seam. The rollers l0 are mounted on pins I I supported by beams 3. In the beams 3 there are also mounted vertical pins for bevel gears l2 cooperating with bevel gears l3 slidably mounted on the shafts and 2 but not rotatable relative to the shafts. On the vertical pins or shafts for the bevel gears l2 there are mounted pulleys Ii for guide belts 1 having verti- 2 cal faces for guiding the edges of the carton blank.

The shaft l4 of the stitching apparatus 22 is driven intermittently by a drive pulley I5 suitably connected with a source of power, not shown. The drive pulley rotates at a constant speed and drives continuously the feed shafts and 2 by means of a belt or chain transmission 30 and a speed changing gear diagrammatically indicated at 26. Every time a series of staples is to be driven into the carton the drive pulley is engaged with the shaft I4 by means of an electrically actuated iron core 2|, the electric arrangement and operation thereof being as follows.

Between the belts 8 there is provided a switch 6, Fig. 3, connected to a source of electric current 3|. When this switch is struck by the front or leading edge 9a of a carton blank 9 fed in the direction of the arrow 32, it is closed and will be kept closed for as long as the carton blank is sliding over it. After a short moment, the front edge of the carton blank strikes a resilient bucket wheel I! which momentarily closes a switch I8 by means of a vane wheel I9 mounted on the same shaft as the bucket Wheel. Thereby an electric circuit is closed, through the members 3|, 33, I6, 34, I8, 35, solenoid 20, and conductor 35. As a result, the solenoid 20 attracts the iron core 2| which, in the manner described hereinbelow, engages the drive pulley l5 with the shaft i4 so as to start the stitching apparatus. In the meanwhile, the switch IB has been opened by means of a spring 23 and is ready to be closed again when the next carton blank arrives. However, the solenoid 20 is still traversed by the current, in spite of the interruption at l8, because of the fact that the iron core 2|, when it starts the stitching apparatus, simultaneously closes a switch 24. The current then flows through the members 3|, 33, Hi, 34, 24, 31, 20, 36. As a result, the stitching apparatus will be operated until the carton blank has passed the switch I6. At this moment, a spring 25 opens the circuit at I6, and the solenoid is deenergized. A spring 28 then pushes back the iron core which disengages the stitching apparatus from the drive pulley I5.

On the shaft I4 of the stitching apparatus there is loosely mounted a disc 38, Fig. 4. A helical spring 39 is provided in an annular space 40 between the outer circumference of the disc 38 .and an inner cylindrical face 45 of the drive pulley I5. One end 4| of the spring is secured to the shaft I4 and the other end 42 is secured to the disc 38. The disc has a radially extending shoulder 43 which in the position illustrated is engaged 3 by the upper end of a rod id connected with the iron core 2 l With the parts in the position shown in Figs. 3 and 4, the shaft M of the stitching apparatus is disengaged from the drive pulley l5. When the solenoid it attracts the iron core, the rod i iis moved downward out of engagement with the shoulder of the disc 38 and the disc is released to the action of the spring 39. The spring 39, which in the position shown in Fig. 4 is in a compressed state, will then expand radially and engage the inner face it of the drive pulley. The frictional contact of the spring 39 with the rotating drive pulley l5 causes the rotation of the spring and the shaft Hi in the direction of the arrow iii. When the rod is again moved upward into the position illustrated, it will arrest the rotation of the disc 38, the spring 39 will compress and relieve its frictional contact with the driving pulley i5, and the connection between the drive pulley and the shaft M will be interrupted.

By means of the speed changing gear 26, the ratio between the speeds of the feed shafts i, 2 and the shaft M can be varied. If the carton blank is fed at a low speed, the stitching apparatus has time to apply a great number of staples while the carton blank passes the same, and vice versa.

The place where the staples are driven into the work is indicated at 27. The distances from the switches i5 and l to the position 2? are adjustable. To this end, the switches are mounted in suitable boxes or carriers ii and iii, respe tively, which are slidably arranged on the frame 23. The distance between the points 2'? and i8 defines the distance between the front edge of the carton blank and the first staple applied, whereas the distance between the points 2? and it defines the distance between the last staple applied and the rear edge of the carton blank. It is thus possible, by changing the positions of the switches it and E8, to predetermine the distances of the staples applied from the front or leading edge and the rear or trailing edge of the carton blank. Due to the fact that the switch it is closed momentarily only, carton blanks can be fed through the machine with very small distances between the rear or trailing edge of a blank and the front or leading edge of the next blank. This would not be possible if the switch is were kept closed until the blank has passed it. In that case, a new blank could be fed only after the preceding blank has left the switch it, since otherwise the stitching apparatus would be disengaged only during the period between the disengagement of the switch it from a blank to the engagement thereof with the next blank.

What I claim is:

1. In a carton stapling machine, a stitching apparatus having a power input shaft, carton ,5 means including feed shafts, driving means for rotating said iced shafts, a clutch for connecting the driving means with said input shaft, a first switch located in the carton path in advance of the working position of the stitching apparatus, as viewed in the direction of movement of the carton, said switch being constructed and arranged to be closed by contact with the leading edge of a carton and to be kept closed ior as long as the carton is sliding thereon and to be opened when the trailing edge of the carton comes out of contact therewith, a second switch located in the carton path behind the working position of the stitching apparatus, said second switch being constructed and arranged to be closed momentarily by contact with the leading edge of said carton, a source of electric curre t connected to said switches, a solenoid connecte to said circuit-breakers to be energized upon clos ing of the switches and to be deenergized upo opening of said first switch, an iron core adapted to be attracted by said solenoid, a third switch operatively connected to said iron core to be closed upon attraction thereof whereby to maintain said solenoid in an energized state irrespective of the opening of said second switch, and means connected with said iron core engaging said clutch when the solenoid is energized and reieasing said clutch when the solenoid is deenergized. 2. In a carton stapling machine, a stitching apparatus having a power input shaft, carton feeding means including feed shafts, driving means for rotating said feed shafts, a clutch for connecting the driving means with said input shaft, a first switch located in the carton path in advance of the working position of the stitching apparatus, as viewed in the direction of movement of the carton, said switch being displaceable in said direction and constructed and arranged to be closed by contact with the. leading edge of a carton and to be closed for as long as the carton is sliding thereon and to be opened when the trailing edge of the carton comes out of contact therewith, a second switch located in the carton path behind the working position of the stitching apparatus, said second switch being displaceable in said direction and constructed and arranged to be closed momentarily by contact with the leading edge of said carton, a source of electric current connected to said switches, a solenoid connected to said circuit-breakers to be energized upon closing of the switches and to be deenergized upon opening or said first switch, an iron core adapted to be attracted by said solenoid, a third switch cperatively connected to said iron core to be closed upon attraction thereof whereby to maintain said solenoid in an energized state irrespective of the opening of said second switch, and means connected with said iron core and engaging said clutch when the solenoid is energized and releasing said clutch when the solenoid is deenergized.

l OLOF EINAR LARSSON.

No references cited.

Certificate of Correction Patent No. 2,509,870 May 30, 1950 OLOF EINAR LARSSON It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 4, lines 16 and 48, for circuit-breakers read switches;

and that the said Letters Patent should be read With these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 5th day of September, A. D. 1950.

THOMAS F. MURPHY,

- Assistant Oommz'ssz'oner of Patents. 

